共查询到20条相似文献,搜索用时 15 毫秒
1.
Shih-Yuan Lin Chih-Ming Wang Kuo-Sheng Kao Ying-Chung Chen Chan-Chih Liu 《Journal of Sol-Gel Science and Technology》2010,53(1):51-58
Molybdenum trioxide (MoO3) films were deposited on ITO/Glass substrates by the sol–gel method using a spin-coating technique and heat treated at various
temperatures under different ambient atmosphere. Effects of the process parameters on the electrochromic properties of MoO3 films were studied using cyclic voltammetry (CV) in a propylene carbonate (PC) non-aqueous solution containing 1 M lithium
perchlorate (LiClO4). Electrochromic MoO3 film on lithium intercalation was investigated by in-situ transmittance measurement during the CV process. The MoO3 films showed reversible recharge ability on Li+/e− intercalation/deintercalation. Experimental results revealed that the heat-treatment temperature, the ambient atmosphere,
and the thickness will have the string influence on the electrochromic properties of MoO3 thin films. X-ray diffraction (XRD) results show that the amorphous MoO3 films can be obtained with the heat-treatment temperature below 300 °C in O2 ambient atmosphere. The optimum electrochromic MoO3 film, with a thickness of 130 nm, exhibits a maximum transmittance variation (ΔT%) of 30.9%, an optical density change (ΔOD) of 0.213, an intercalation charge (Q) of 8.47 mC/cm2, an insertion coefficient x in Li
x
MoO3 was 0.21 and a coloration efficiency (η) of 25.1 cm2/C between the colored and bleached states at a wavelength (λ) of 550 nm. 相似文献
2.
This study describes the In2S3 semiconductor thin film coating on glass substrate by sol–gel method. The In2S3 thin film samples were prepared and examined by the X-ray diffraction (XRD), the UV–visible optical absorption and transmission
study, and the Scanning Electron Microscope (SEM) image analyses. The XRD analysis results show that the In2S3 semiconductor thin films prepared by sol–gel method is formed at T~360–520 °C temperature interval. Band gap energy and optical
absorption spectrum analysis of the In2S3 thin films reveal that Eg~2.51 eV for the In2S3 thin films. According to the EDX result the film was In-rich with the In/S = 1.42 ratio. The thickness of prepared In2S3 layer is about 400 nm. 相似文献
3.
A sol–gel route was developed to prepare pure ultrafine LiTaO3 powders using Ta2O5, Li2CO3, citric acid (CA) as chelating agent, ethylene glycol (EG) as esterification agent and polyethylene glycol (PEG) as dispersant.
The effects of pH value and heat treatment temperature of powder precursor on the synthesis of LiTaO3 powders were investigated. The phase content and morphology of the final product were evaluated by XRD, SEM and TEM. A transparent
gel was produced when heating a mixed-solution of CA, EG, Li and Ta ions with a molar ratio of [CA]:[EG]:[Li]:[Ta] = 3.0:6.0:1.0:1.0
and 2‰ PEG additions with a pH value of 7 at water bath temperature of 80 °C. The results showed that single phase LiTaO3 powders with average particle sizes of nanometers were produced after heat treatment of the powder precursor at 650, 700,
800, and 900 °C respectively for 2 h. 相似文献
4.
Preparation and characterization of TiO<Subscript>2</Subscript> sol–gel modified nanocomposite films
In this study, the role of TiO2 MT-150A loading in the polymeric sol was investigated for the synthesis of immobilized TiO2 nanocomposite films on glass substrate using the MT-150A nanoparticles-modified sol–gel method. The nanocomposite film properties
were examined using different material characterization techniques including X-ray diffraction, X-ray photoelectron spectroscopy,
field emission scanning electron microscopy, UV–Vis spectrophotometer, Scotch tape test and pencil hardness test. The hydrophilicity
of films during UV/Vis irradiation and storage in a dark place were evaluated by a contact angle analyzer. The MT-150A loading
had a significant effect on the amount of crystallite phases in the films. However, increasing the MT-150A loading in the
sol resulted in an increase in rutile phase content. In addition, increasing MT-150A loading in the sol yielded films with
higher hydrophilicity but a concentration of 10–30 g/L MT-150A in the sol was found as the maximum for obtaining films with
good adherence on the glass substrate. 相似文献
5.
Nursen Avci Philippe F. Smet Hilde Poelman Nigel Van de Velde Klaartje De Buysser Isabel Van Driessche Dirk Poelman 《Journal of Sol-Gel Science and Technology》2009,52(3):424-431
Stable TiO2 sols were prepared using two non-aqueous sol–gel processes with titanium n-butoxide and titanium isopropoxide, respectively. Crystallization and phase transitions of powders and thin films were studied
by ex situ and in situ X-ray diffraction. For both methods, TiO2 began to crystallize around 320 °C in air. Using helium instead of air during heat treatment slowed down the crystallization
and substoichiometric powders were formed. TiO2 thin films were obtained by spin coating. The morphology of the films was evaluated using scanning electron microscopy. The
films were homogeneous and transparent in the visible range. The effect of the heating atmosphere and the type of substrate
was investigated. 相似文献
6.
N. P. Simonenko E. P. Simonenko V. G. Sevastyanov N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2016,61(7):805-810
The synthesis of hydrolytically active heteroligand coordination compounds [M(C5H7O2)3?x(C5H11Oi)x] (M = Fe3+ and Y3+) using iron and yttrium acetylacetonates has been studied. The gel formation kinetics in solutions of these compounds upon hydrolysis and polycondensation has also been studied. Thin films of a solution of these precursors have been applied to polished sapphire substrates by dip coating technology. The crystallization of nanostructured yttrium iron garnet (Y3Fe5O12) films during heat treatment of xerogel coatings under various conditions has been studied. How the phase composition, microstructure, and particle size depend on the synthesis parameters has been recognized. 相似文献
7.
M. S. Bhuwaneswari L. Dimesso W. Jaegermann 《Journal of Sol-Gel Science and Technology》2010,56(3):320-326
Lithium intercalation materials are of special interest as cathodes in rechargeable batteries. An uncomplicated sol–gel process
has been used for the synthesis of Li–Co phosphates powders and, for the first time, of LiCoPO4 films. The powders were prepared from aqueous solutions, containing Li, Co and phosphate precursors to which acid citric
and ethylene glycol was added, during the drying process at 75 °C. The X-ray diffraction patterns of the prepared powders
confirmed the presence of LiCoPO4 with an olivine-like structure as main phase. The morphological investigations of the powder showed a platelet-like structure
with an average grain size of 0.75 μm. The films of LiCoPO4 were deposited onto ITO glass substrates with the combination of the dip-coating process under the same conditions. Finally,
the films were annealed in inert atmosphere at 300 °C. The morphological investigations reveal a smooth and homogeneous surface
of the prepared Li–Co phosphate films. The preliminary electrical investigation on the prepared LiCoPO4 films showed lithium ions electrochemical activity in the range 3.0–4.5 V. 相似文献
8.
Yang Ren Gaoyang Zhao Chenxi Zhang Yuanqing Chen 《Journal of Sol-Gel Science and Technology》2012,61(3):565-569
CuAlO2 thin films were deposited on quartz substrates by sol–gel process using copper acetate monohydrate and aluminum nitrate nanohydrate
as starting materials and isopropyl alcohol as solvent. The influence of annealing temperature on the film structure and the
phase evolution of CuAlO2 films were investigated, so as to obtain CuAlO2 films with superior performance. The phase compositions of the films were dependent on the annealing temperature. The films
annealed at temperatures below 400 °C were amorphous while those annealed above 400 °C were polycrystalline. The phases of
CuO and CuAl2O4 appeared gradually with the increase of annealing temperature. When the heat treatment temperature was elevated to 900 °C,
the uniform and dense films with single phase of CuAlO2 were obtained, with a resistivity of 15 Ωcm. The transmittance of the 310 nm-thick CuAlO2 film is 79% at 780 nm and the direct optical band gap is 3.43 eV. 相似文献
9.
Elisa Marenna Carmela Aruta Elza Bontempi Antonio Cassinese Paolo Colombi Laura E. Depero Pasquale Pernice Antonio Aronne 《Journal of Sol-Gel Science and Technology》2009,49(1):106-111
The morphological and electrical characterization of transparent nanostructured LiNbO3–SiO2 thin films synthesized by a novel sol–gel route is reported. Films annealed at different temperatures exhibit different size
of the nanocrystals, as demonstrated by Atomic Force Microscopy and Glancing Incidence X-ray diffraction. The dc electrical
measurements performed on planar devices reveal electrical bistability. A clear relationship between the electrical bistability
and the size of LiNbO3 nanocrystals embedded in the matrix is observed. 相似文献
10.
C. K. Ghosh S. R. Popuri T. U. Mahesh K. K. Chattopadhyay 《Journal of Sol-Gel Science and Technology》2009,52(1):75-81
Nanocrystalline powders of CuAlO2 were synthesized through sol–gel method using nitrate-citrate route and also through solid state reaction method. We used
a new set of precursor materials for the synthesis of CuAlO2 through sol–gel route which were not reported in the past. A little lowering of the synthesis temperature (1,000 °C) was
observed in case of sol–gel process compared to the solid state reaction method (1,100 °C) and also at shorter time duration.
The particle size of the synthesized powders was determined through small angle X-ray scattering. It has been observed that
the particle size prepared by nitrate-citrate technique is less than the particle size prepared by the solid-state reaction
method. Chemical states of the atomic species were determined by X-ray photoelectron spectroscopy. The formation of phase
pure CuAlO2 were also confirmed by Fourier transformed infrared spectroscopy. A number of solvents were also used for finding the best
possible combinations for obtaining phase pure CuAlO2 at 1,000 °C and it was observed that only the combination of nitrate salts, citric acid and ethanol resulted phase pure CuAlO2. 相似文献
11.
E. P. Simonenko N. P. Simonenko V. G. Sevastyanov N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2016,61(12):1483-1498
Sol–gel technology was used to chemically modify the surface of HfB2 powders with highly dispersed silicon carbide using two carbothermy protocols: (1) under heating to 1500°С in flowing argon (100 mL/min) without exposure and (2) under dynamic vacuum conditions (p ~ 1 × 10–5–1 × 10–6 MPa) at 1400°С with 4-h exposure. The phase composition and microstructural features of the thus-prepared HfB2/xSiC (x = 10–65 vol %) composite powders were studied. The products prepared by the second protocol showed an enhanced oxidation resistance in the range 20–1400°C in flowing air compared to individual HfB2. 相似文献
12.
Nanocrystalline single-phase neodymium monoaluminate (NdAlO3) has been prepared from neodymium oxide and aluminium nitrate by modified Pechini’s method. Malic acid has been used for
the first time as a new complexing agent in the sol–gel process. It has facilitated, without adding 1,2-ethanediol, a low-temperature
synthesis at 1,050 °C compared to the temperature of 1,630 °C needed for the solid-state preparation. The characterisation
of the nanoparticles has been carried out by X-ray diffraction, scanning electron microscopy, transmission electron microscopy,
X-ray photoelectron spectroscopy, and infrared spectroscopy in the range 75–4,000 cm−1. The smallest particles have size of 30 nm and are anisometric; agglomerates of particles have been also observed. The material
has pyknometric density of 3.956 g/cm3 at T = 293.15 K and specific surface area 5.2 m2/g. The binding energies of O 1s, Al 2p, Nd 3d, and Nd 4d electrons have been found chemically shifted in NdAlO3 compared to the values for the respective elements. 相似文献
13.
N. P. Simonenko V. A. Nikolaev E. P. Simonenko N. B. Generalova V. G. Sevastyanov N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2016,61(12):1505-1511
This study is concerned with the preparation of hydrolytically active heteroligand complex [Ti(OC4H9)3.61(O2C5H7)0.39] from titanium butoxide and acetylacetone and with the gel formation kinetics in a solution of this complex upon hydrolysis and polycondensation. Single-layer and double-layer thin films of a solution of this precursor were coated on polished silicon substrates using the dip-coating method. The crystallization of nanostructured titania films during the heat treatment of these xerogel coatings was studied using various protocols; the anatase–rutile phase transition temperature was found to depend on the film thickness. The effects of the precursor solution viscosity on the film thickness and crystallite size were determined. 相似文献
14.
Jia-jia Ji Hui Sun Xiang-yu Mao Wei Wang Xiao-bing Chen 《Journal of Sol-Gel Science and Technology》2012,61(2):328-331
The Bi5FeTi3O15 (BFTO) films of layered structure have been fabricated on Pt/Ti/SiO2/Si substrates by the sol–gel method. The thermal decomposition behaviors of precursor powder were examined using thermo-gravimetric
and differential scanning calorimeters analysis. The optimal heat treatment process for BFTO films were determined to be low-temperature
drying at 200 °C for 4 min and high-temperature drying at 350 °C for 5 min followed by annealing at 740 °C for 60 min, which
led to the formation of compact films with uniform grains of ~300 nm. The structural, surface topography, ferroelectric and
magnetic properties of the films were investigated. The remnant polarization (2P
r) of BFTO thin films under an applied electric field of ~550 kV/cm are determined to be 67.5 μC/cm2
. Meanwhile, the weak ferromagnetic properties of the BFTO films were observed at room temperature. 相似文献
15.
Chiwon Kang Jung-Hyun Park Dongna Shen Hosang Ahn Minseo Park Dong-Joo Kim 《Journal of Sol-Gel Science and Technology》2011,58(1):85-90
(K0.5 Na0.5)NbO3 (KNN) perovskite materials have been developed as a promising lead-free piezoelectric material for environmentally benign
piezoelectric devices. KNN films with about 320 nm thickness were fabricated on Pt(111)/SiO2/Si(100) substrates by a sol–gel method from stoichiometric and A-site ion excess precursor solutions. Two different annealing
methods were also used to investigate the crystallographic evolution of the films. A layer-by-layer annealing process results
in highly (001) oriented KNN from the annealing temperature of 550 °C, while the final annealing method leads to weaker crystalline
peaks with a random orientation. The KNN films from the K and Na excess precursor solutions show similar crystallization behavior.
However, the ferroelectric hysteresis loops of the films were greatly improved by compensating for an A-site vacancy. In particular,
the KNN films from K-excess precursor solutions show better ferroelectric properties compared to the films prepared from Na
excess solutions. 相似文献
16.
Davinder Singh Nafa Singh Sunil Dutta Sharma Chander Kant C. P. Sharma R. R. Pandey K. K. Saini 《Journal of Sol-Gel Science and Technology》2011,58(1):269-276
Nickle and iron doped TiO2 thin films were prepared on glass substrates by sol–gel dip coating process. Indirect and direct optical energy gaps were
calculated with the incorporation of different concentrations of both the ions. Indirect bandgap was found to be a strong
function of the dopant concentration, whereas direct energy gap has negligible dependence on the nature of dopant and its
concentration. Direct energy gap has always been found to retain a value higher than the indirect energy gap. Variation of
observed energy gap properties shows a trend similar to that reported on the basis of numerical calculations or the samples
obtained by other techniques. Increase in refractive index and corresponding density of the film sample does not support the
change in turn over frequency. The influence of crystalline phase change is also ruled out by XRD investigations. It is concluded
that red shift of band edge absorption takes place by incorporation of dopant and sol–gel dip coating technique offers an
effective low cost route to the production of these coatings. 相似文献
17.
Zuci Quan Hao Hu Sheng Xu Wei Liu Guojia Fang Meiya Li Xingzhong Zhao 《Journal of Sol-Gel Science and Technology》2008,48(3):261-266
Bi1−x
Ce
x
FeO3 (x = 0, 0.05, 0.1, 0.15 and 0.20) (BCFO) thin films were deposited on Pt/TiN/Si3N4/Si substrates by sol–gel technique. Crystal structures, surface chemical compositions and bonding states of BCFO films were
investigated by X-ray diffraction and X-ray photoelectron spectroscopy (XPS), respectively. Compared to BiFeO3 (BFO) counterparts, the fitted XPS narrow-scan spectra of Bi 4f7/2, Bi 4f5/2, Fe 2p3/2, Fe 2p1/2 and O 1s peaks for Bi0.8Ce0.2FeO3 film shift towards higher binding energy regions by amounts of 0.33, 0.29, 0.43, 0.58 and 0.49 eV, respectively. Dielectric
constants and loss tangents of the BCFO (x = 0, 0.1 and 0.2) film capacitors are 159, 131, 116, 0.048, 0.041 and 0.035 at 1 MHz, respectively. Bi0.8Ce0.2FeO3 film has a higher remnant polarization (P
r = 2.04 μC/cm2) than that of the BFO (P
r = 1.08 μC/cm2) at 388 kV/cm. Leakage current density of the Bi0.8Ce0.2FeO3 capacitor is 1.47 × 10−4 A/cm2 at 388 kV/cm, which is about two orders of magnitude lower than that of the BFO counterpart. Furthermore, Ce cations are
feasibly substituted for Bi3+ in the Bi0.8Ce0.2FeO3 matrix, possibly resulting in the enhanced ferroelectric properties for the decreased grain sizes and the reduced oxygen
vacancies. 相似文献
18.
(BiFeO3)1−x
–(BaTiO3)
x
solid solution thin films are grown on Pt/Ti/SiO2/Si substrates by chemical solution deposition method. Films with x = 0.00, 0.05 and 0.10 were prepared by annealing at 500°C. X-ray diffraction patterns indicate that the pure BiFeO3 film adopts random orientation while the solid solution films are highly (100) preferentially oriented. Improved electric
property at room temperature was observed in the BaTiO3 incorporated BiFeO3 films. The remanent polarization of the film with x = 0.0, 0.05 and 0.10 are 76.6, 51.9 and 19.7 μC/cm2 respectively under a measuring electric field of 0.94 MV/cm. The BaTiO3 incorporated BiFeO3 films show improved fatigue endurance. By the solid solution with BaTiO3, the leakage current density is reduced effectively. 相似文献
19.
MgNb2O6 nanocrystalline powders have been synthesized at a low temperature by improved citrate sol–gel method in this paper. The
high quality solution of Nb5+ was prepared using Nb2O5 as the starting material. The crystal structure and microstructure of MgNb2O6 powders were characterized by XRD and SEM techniques, and the effects of preparation craft including pH value and the proportion
of citric acid to the niobium ions on the crystal structure and microstructure of powders were also investigated. XRD and
TG/DTA results show that the single phase of MgNb2O6 for synthesized powders can be obtained by calcining the precursor at 700 °C. SEM results indicate that the average particle
size of MgNb2O6 exhibits a significantly dependence on the pH values and the proportion of citric acid to the niobium ions, where it was
found that particle size of a 20 nm can be obtained for the MgNb2O6 powders by sol–gel process. 相似文献
20.
H. Bensouyad D. Adnane H. Dehdouh B. Toubal M. Brahimi H. Sedrati R. Bensaha 《Journal of Sol-Gel Science and Technology》2011,59(3):546-552
We have studied structural and optical properties of thin films of TiO2, doped with 5% ZnO and deposited on glass substrate (by the sol–gel method). Dip-coated thin films have been examined at
different annealing temperatures (350–450 °C) and for various layer thicknesses (89–289 nm). Refractive index, porosity and
energy band gap were calculated from the measured transmittance spectrum. The values of the index of refraction are in the
range of 1.97–2.44, the porosity is in the range of 0.07–0.46 and the energy band gap is in the range of 3.32–3.43. The coefficient
of transmission varies from 50 to 90%. In the case of the powder of TiO2, doped with 5% ZnO, and aged for 3 months in ambient temperature, we have noticed the formation of the anatase phase (tetragonal
structure with 20.23 nm grains). However, the undoped TiO2 exhibits an amorphous phase. After heat treatments of thin films, titanium oxide starts to crystallize at the annealing temperature
350 °C. The obtained structures are anatase and brookite. The calculated grain size, depending on the annealing temperature
and the layer thickness, is in the range of 8.61–29.48 nm. 相似文献